*{
	margin: 0;
	padding: 0;
}
#wrap{
	position: relative;
	width: 300px;
	height: 400px;
	border: 1px solid;
	margin: 0 auto;
	.inner{
			position: absolute;
			left: 0;
			right: 0;
			top: 0;
			bottom: 0;
			margin: auto;
			background: blue;
			height: 100px;
			width: 100px;
		}
}